Stanley, Wendell Meredith (1904-1971) was an American biochemist who won a share of the 1946 Nobel Prize in chemistry for his preparation of enzymes and virus proteins in a pure form. He shared the prize with John Howard Northrop and James Batcheller Sumner, who did related work on viruses.

Stanley's original career plan to become a football coach was rerouted after he visited the University of Illinois and met a chemistry professor as an undergraduate at Earlham College in Richmond, Indiana. Inspired by that trip, he did his graduate work at Illinois and received his Ph.D. degree in chemistry in 1929. He then did post-doctoral work in Germany on a National Research Council Fellowship and, upon his return to the U.S. in 1931, began working at the Rockefeller Institute (now Rockefeller University). Stanley moved to Rockefeller's plant pathology division in 1932 and began studying viruses, of which little was then known.

There, building on the earlier work of scientists John Howard Northrop and Moses Kunitz, who had isolated and crystallized enzyme proteins, Stanley began studying the tobacco mosaic virus (TMV), which he eventually succeeded in crystallizing. This brought a flurry of questions over whether viruses were actually living organisms or not, and resulted in his Nobel Prize. Stanley also showed that the tobacco mosaic virus was a protein molecule.

Stanley's work paved the way for many further advances in virology, including his and his colleagues' development of an influenza vaccine during World War II (1939–1945). He received the American Association for the Advancement of Science Prize, the Rosenberger Medal, Isaac Adler Prize, Scott Award, the Gold Medal from the American Institute of New York, the Copernican Citation, the Nichols, Gibbs, and Franklin Medals, the Presidential Certificate of Merit, the Modern Medicine Award, and the Distinguished Service Medal from the American Cancer Society.